Add special environment mapping modes to CoronaBitmap

[Ludvik Koutny]

(Moving mantis feature requests to forum)

Modes like Hemispherical (flat ground), cube cross,  mirror ball and so on, so there is at least some point of using CoronaBitmap.

[Ondra]

duplicate thread with some resources: https://forum.corona-renderer.com/index.php/topic,12733.0.html

[Ondra]

added